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Home-Made IEMs - Page 124

post #1846 of 5636
Quote:
Originally Posted by vector1 View Post
 

 

Unless I'm reading the FR graphs wrongly, I thought the DTECs handle that range particularly well? At least, a WBFK + DTEC should provide sufficient upper mid range response, coupled with my acoustic tuning by increasing inner diameter of passages to ~1.4mm. I can increase this further to boost the 1-2kHz response if I feel that the mids are too recessed.

DTEC with tubing length around 16mm will move peaks to 1,5kHz and further to the left. and you won't be able to level it down much by tubing diameter. As I understand you'll be using 2200 damper which will affect range between 800Hz and 6kHz decreasing response by around 4-6dB.

WBFK, I don't know where you plan to cut it, but it has very flat response and peak around 5-8kHz (depending on tubing).

What I'm saying your frequency response will look like this - bump in bass and mid bass. practically flat (~2-3dB differences) between 700-4kHz and peak at 8-10kHz and then practically flat to 20kHz

It will sound mid-recessed, vocals may sound hollow. Bass and highs will be dominant though.

 

It also comes down to how good you'll be able to handle phase canceling. You may end up with big gap or peak in certain frequencies.


Edited by piotrus-g - 6/22/14 at 8:56am
post #1847 of 5636

http://s57.radikal.ru/i156/1406/cd/8ac60999c4fa.jpg

 

http://i065.radikal.ru/1406/d6/b52c46ea07c8.jpg

 

http://s006.radikal.ru/i214/1406/55/85a353174287.jpg

 

Could you help me please. What wire used here, is it copper litz or something else? what is better to use wire?


Edited by koshernyituzzz - 6/22/14 at 11:34am
post #1848 of 5636

Litz wire.

post #1849 of 5636
Quote:
Originally Posted by piotrus-g View Post
 

Litz wire.

 

Quote:
Originally Posted by piotrus-g View Post
 

DTEC with tubing length around 16mm will move peaks to 1,5kHz and further to the left. and you won't be able to level it down much by tubing diameter. As I understand you'll be using 2200 damper which will affect range between 800Hz and 6kHz decreasing response by around 4-6dB.

WBFK, I don't know where you plan to cut it, but it has very flat response and peak around 5-8kHz (depending on tubing).

What I'm saying your frequency response will look like this - bump in bass and mid bass. practically flat (~2-3dB differences) between 700-4kHz and peak at 8-10kHz and then practically flat to 20kHz

It will sound mid-recessed, vocals may sound hollow. Bass and highs will be dominant though.

 

It also comes down to how good you'll be able to handle phase canceling. You may end up with big gap or peak in certain frequencies.

 

One thing to note is that with my 3d printing, tubing size/length is completely adjustable as long it fits in the shell. This is because I'm literally printing the boot to fit the drivers in, as can be seen in the photo during my testing. The shell is also very small compared to westone's w60 series, I just tested them the day before. If I need more space, I can always lengthen the shell up to 5mm.

 

Interesting. I can make several changes, could you give an opinion on that?

 

1) Move the DTEC forward to minimize distance/shift peaks? I can do that by around 2-3mm, because currently the WBFK is nearly right beside the output channel to maximize sound output.

 

2) 2200 damper will only be on the CI channel, closer to the receiver, not on the main nozzle. This isn't so much of a change as what I was initially planning, so is this a good idea?

 

3) Phase cancelling can be somewhat attenuated by reversing the polarity of the drivers? I read somewhere that the deep cancellation becomes a small peak if reversed. I'll have to do that by ear and running a sweep.
 

I'm going to tune the drivers by ear as I have just got a load of variable resistors and small caps to test out.

 

As I read more and more, designing a passive crossover just feels like a shot in the dark, even with measurements, and an active crossover seems like the only way to really get good results. After this set, I think I'll run my own design of active crossovers if I reshell it into DIY customs for my ear.

 

This is my current testing shell (got a long nozzle for the tip).

 

post #1850 of 5636

When I was reading this

 

CI22955 - use as a full range with 3300 ohm damper 16mm-22mm tubing

ED26869 - use 1-2,2uF cap - 13-16mm tubing 680 ohm damper

WBFK - connect it in second order after ED with another 1uF 10-13mm tubing 680 damper

 

Do I have to connect any of the drivers in reverse polarity? I couldn't get my head around the high frequency drivers, crossovers, and how they affect phase haha...

post #1851 of 5636
Quote:
Originally Posted by Xymordos View Post
 

When I was reading this

 

CI22955 - use as a full range with 3300 ohm damper 16mm-22mm tubing

ED26869 - use 1-2,2uF cap - 13-16mm tubing 680 ohm damper

WBFK - connect it in second order after ED with another 1uF 10-13mm tubing 680 damper

 

Do I have to connect any of the drivers in reverse polarity? I couldn't get my head around the high frequency drivers, crossovers, and how they affect phase haha...


connect CI in phase, ED in reverse phase and WBFK with 2nd order crossover in the same phase as CI or in reverse polarity if you use 1st order.

post #1852 of 5636

Thanks for your help! All my drivers will be arriving at the end of the week for me to solder :P 

 

What is the method to calculate the phase shifts? I remember there was a post that had the description written out, but I can't seem to find it anymore.

post #1853 of 5636
Quote:
Originally Posted by vector1 View Post
 

 

 

One thing to note is that with my 3d printing, tubing size/length is completely adjustable as long it fits in the shell. This is because I'm literally printing the boot to fit the drivers in, as can be seen in the photo during my testing. The shell is also very small compared to westone's w60 series, I just tested them the day before. If I need more space, I can always lengthen the shell up to 5mm.

 

Interesting. I can make several changes, could you give an opinion on that?

 

1) Move the DTEC forward to minimize distance/shift peaks? I can do that by around 2-3mm, because currently the WBFK is nearly right beside the output channel to maximize sound output.

 

2) 2200 damper will only be on the CI channel, closer to the receiver, not on the main nozzle. This isn't so much of a change as what I was initially planning, so is this a good idea?

 

3) Phase cancelling can be somewhat attenuated by reversing the polarity of the drivers? I read somewhere that the deep cancellation becomes a small peak if reversed. I'll have to do that by ear and running a sweep.
 

I'm going to tune the drivers by ear as I have just got a load of variable resistors and small caps to test out.

 

As I read more and more, designing a passive crossover just feels like a shot in the dark, even with measurements, and an active crossover seems like the only way to really get good results. After this set, I think I'll run my own design of active crossovers if I reshell it into DIY customs for my ear.

 

This is my current testing shell (got a long nozzle for the tip).

 

I see

 

1. move  DTEC an CI to the front and WBFK as far to the back as possible

2. You have to use damper on DTEC unless you're running it with low pass.

3. That' s true but will be difficult to judge by ear unless you have golden ears.

 

The problem you have here is you've chosen two woofers and a super tweeter. Neither DTEC nor CI have good 1-4kHz range.

Probably the best option for you would be following:

DTEC - low pass between 200-800Hz

CI as full-range with resistor ~40Ohm.

WBFK from around 2-3kHz

 

In my mind this will result in most balanced frequency response.

post #1854 of 5636

I am playing around with the knowles GQ-30783 driver today, I am getting a rather bright response from it with no damper and a tube length around 3 cm, I tested it with a tube length of around 7 cm and I liked that sound quite a bit but that is far to long of a tube to work in a shell. What damper should I use to get a similar response? I have 680 on hand but I will need to order anything else.

post #1855 of 5636
Quote:
Originally Posted by piotrus-g View Post
 

I see

 

1. move  DTEC an CI to the front and WBFK as far to the back as possible

2. You have to use damper on DTEC unless you're running it with low pass.

3. That' s true but will be difficult to judge by ear unless you have golden ears.

 

The problem you have here is you've chosen two woofers and a super tweeter. Neither DTEC nor CI have good 1-4kHz range.

Probably the best option for you would be following:

DTEC - low pass between 200-800Hz

CI as full-range with resistor ~40Ohm.

WBFK from around 2-3kHz

 

In my mind this will result in most balanced frequency response.

 

Interesting. I have tested with sine wave generators, and I can detect a very perceptible dip at the 1.8k-2k range when listening to just the CI/DTECs, so you're absolutely right.

 

I'm still awaiting the arrival of my WBFKs which I destroyed, but I think you're also right about WBFK not contributing to the 1-4k range.

 

I have made several modifications as you recommend, but why would you push WBFK to the back? 

 

Also,on further reflection I think there might not be space to squeeze the damper into the CI channel alone because I need at least 5mm, and I currently have around 2.5mm space, unless I lengthen the entire IEM which I'm trying not to at the moment.

 

Do you have any recommendations on a different driver that is suitable for the midrange?

 

Here is my latest set for testing now.

 

This is the drivers in the boot, WBFK moved back, widened the bore on DTEC and CI and prepared rubber plugs to hold the driver nozzles in place, made the inside a little smoother in case that affects the sound.

 

This is the exterior, as MuZo said, the nozzle ID is 2.2 and OD of 3.2.

 

post #1856 of 5636

^ awesome CAD drawing there! 

Quote:

Originally Posted by piotrus-g View Post
 

I see

 

1. move  DTEC an CI to the front and WBFK as far to the back as possible

2. You have to use damper on DTEC unless you're running it with low pass.

3. That' s true but will be difficult to judge by ear unless you have golden ears.

 

The problem you have here is you've chosen two woofers and a super tweeter. Neither DTEC nor CI have good 1-4kHz range.

Probably the best option for you would be following:

DTEC - low pass between 200-800Hz

CI as full-range with resistor ~40Ohm.

WBFK from around 2-3kHz

 

In my mind this will result in most balanced frequency response.

The CI is very sensitive to dampening resistors, if it were me I wouldn't go as far as 40ohm, not only you are reducing its SPL but bass decay will also be significantly reduced as a result. 10-20ohm should be enough to keep it controlled without losing too much of its signature (personally I always stay within 13-18ohm). If it's still too loud vector might need to consider another driver as sub woofer.

post #1857 of 5636
Quote:
Originally Posted by tranhieu View Post
 

The CI is very sensitive to dampening resistors, if it were me I wouldn't go as far as 40ohm, not only you are reducing its SPL but bass decay will also be significantly reduced as a result. 10-20ohm should be enough to keep it controlled without losing too much of its signature (personally I always stay within 13-18ohm). If it's still too loud vector might need to consider another driver as sub woofer.

I have several pots that I'm just tuning to find the right sound blindly :D

 

Currently I'm listening to the reversed arrangement (CI full range on resistor, DTEC on lowpass and it's pretty good!)

 

Could you suggest alternatives? I'm open to getting an alternative driver, and using either CI or DTEC as the woofer.

post #1858 of 5636
Quote:
Originally Posted by vector1 View Post
 

I have several pots that I'm just tuning to find the right sound blindly :D

 

Currently I'm listening to the reversed arrangement (CI full range on resistor, DTEC on lowpass and it's pretty good!)

 

Could you suggest alternatives? I'm open to getting an alternative driver, and using either CI or DTEC as the woofer.

If you are willing to get a tray of 25 same drivers from Sonion then I will throw in the 3300, 1700 and 3800. The BK might make a good substitute but their lows' signature is a far cry from the CI, as well as other specs. You might be better off with just the DTEC alone as woofer.

 

Anyway, CI is pretty much the best sub woofer-like driver you can get in single units from Knowles. It has nice sub bass, so-so mid bass, not so good upper bass but that can be solved with a high order filter. Their only down side is the long decay & slow response, which would fit slow/relaxing music like jazz or some vocal. Size factor is another thing needs considering but they're not too bad compared to the DTEC for example. 

 

If you think what you're hearing is good then no need to switch. You're not tuning for someone else anyway.


Edited by tranhieu - 6/23/14 at 8:31pm
post #1859 of 5636
Quote:
Originally Posted by tranhieu View Post
 

If you are willing to get a tray of 25 same drivers from Sonion then I will throw in the 3300, 1700 and 3800. The BK might make a good substitute but their lows' signature is a far cry from the CI, as well as other specs. You might be better off with just the DTEC alone as woofer.

 

Anyway, CI is pretty much the best sub woofer-like driver you can get in single units from Knowles. It has nice sub bass, so-so mid bass, not so good upper bass but that can be solved with a high order filter. Their only down side is the long decay & slow response, which would fit slow/relaxing music like jazz or some vocal. Size factor is another thing needs considering but they're not too bad compared to the DTEC for example. 

 

If you think what you're hearing is good then no need to switch. You're not tuning for someone else anyway.

 

I think 25 drivers will be kind of out of my budget haha!

 

What about the DWFK as a mid? I haven't see anyone use it yet.

post #1860 of 5636
Quote:
Originally Posted by vector1 View Post
 

 

I think 25 drivers will be kind of out of my budget haha!

 

What about the DWFK as a mid? I haven't see anyone use it yet.

Some companies used it before. This list might give you an idea what drivers are commonly used in the market https://docs.google.com/spreadsheet/pub?key=0AoHxSlnX1Un0dC1iMS1qN1VMODV4Wnd0a0xiNHVXLVE&output=html&richtext=true

 

It is managed by this guy http://84audio.blog27.fc2.com/ and various members of 2chan. You might find some useful info there, the CIEM diy community in Japan is very active.

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